US9696362B2 - Test and measurement device with a pistol-grip handle - Google Patents

Abstract

A clamp meter configured to receive a removable and rechargeable battery pack. The clamp meter includes a main body having a first axis, a handle, a clamp, a trigger, and a display. The handle has a second axis and includes a first recess configured to receive the battery pack. The first recess includes at least first and second electrical terminals which are exposed when the battery pack is not inserted into the first recess. The second axis forms an oblique angle with the first axis, and the battery pack is inserted into the first recess along the second axis. The clamp is coupled to the main body, aligned with the first axis, and operable to measure an electrical characteristic of a conductor based on an induced current. The trigger is operable to selectively open and close the clamp, and the display configured to display an indication of the electrical characteristic.

Description

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 14/270,430, filed May 6, 2014, which is a continuation of U.S. patent application Ser. No. 13/626,667, filed Sep. 25, 2012, which is a continuation of U.S. patent application Ser. No. 12/936,808, now U.S. Pat. No. 8,274,273, which entered the U.S. under 35 U.S.C. §371 on Apr. 1, 2011 as a national-stage entry of PCT Application No. PCT/US2009/040101, filed Apr. 9, 2009, which is a continuation-in-part of U.S. patent application Ser. No. 12/399,835, filed Mar. 6, 2009, now U.S. Pat. No. 8,251,157, the entire contents of all of which are hereby incorporated by reference. U.S. patent application Ser. No. 12/936,808 also claims the benefit of U.S. Provisional Patent Application No. 61/043,455, filed on Apr. 9, 2008, and U.S. Provisional Patent Application No. 61/095,053, filed on Sep. 8, 2008, the entire contents of both of which are hereby incorporated by reference.

BACKGROUND

Test and measurement devices, such as digital multi-meters (“DMM's”), clamp meters, thermometers, stud sensors, and the like, are powered by replaceable or rechargeable alkaline batteries. For example, a typical test and measurement device includes a receiving area on a bottom or back face of the device that is adapted to receive a plurality (e.g., 2, 3, 4, etc.) of alkaline batteries. The batteries are secured in the receiving area via a removable door or plate which is fixedly attached to the device's housing. The alkaline batteries, which typically have a nominal voltage of 1.5V, are connected in series to provide operational power to the devices.

In many instances, these devices have dedicated functionalities. For example, a DMM is capable of measuring electrical characteristics such as voltage and current and displaying an indication of the measured electrical characteristic. Clamp meters have similar or identical functionality to the DMM, but differ in the manner in which some of the electrical characteristics are measured (e.g., using inductive coupling). Thermometers, such as infrared (“IR”) thermometers, include a detector and a laser source for projecting an indication of the location or size of a sensed area. Stud sensors include the capability of detecting wooden or metal studs hidden behind a surface and providing an indication of a sensed stud via light emitting diodes (“LEDs”) or an audible indicator such as a small speaker.

SUMMARY

In one embodiment, the invention provides a test and measurement device configured to receive a removable and rechargeable battery pack. The test and measurement device includes a main body having a first axis, a handle having a second axis, a first recess, and a second recess. The first recess includes a mating interface for receiving, along the second axis, a first attachment operable to provide power to the test and measurement device, and the second recess is configured to receive a second attachment operable to provide operational control for the test and measurement device. The handle is offset from the main body of the test and measurement device, and is attached to a lower portion of the main body along the second axis such that the handle forms an oblique angle with respect to the first axis.

In another embodiment, the invention provides a clamp meter configured to receive a removable and rechargeable battery pack. The clamp meter includes a main body having a first axis, a handle, a clamp, a trigger, and a display. The handle has a second axis and includes a first recess configured to receive the battery pack. The first recess includes at least first and second electrical terminals which are exposed when the battery pack is not inserted into the first recess. The second axis forms an oblique angle with the first axis, and the battery pack is inserted into the first recess along the second axis. The clamp is coupled to the main body, aligned with the first axis, and operable to measure an electrical characteristic of a conductor based on an induced current. The trigger is operable to selectively open and close the clamp, and the display is configured to display an indication of the electrical characteristic.

In another embodiment, the invention provides a method of operating a clamp meter that includes a main body, a handle, a clamp, and a pair of electrical leads. The method includes powering the clamp meter with a removable battery pack inserted into a recess of the handle; sensing, using the clamp, a first electrical characteristic based on an induced current; measuring, based on signals received through the pair of electrical leads, a second electrical characteristic; and displaying, on a display, an indication of the first electrical characteristic and the second electrical characteristic. The pair of electrical leads are operable to receive a pair of electrical probes, the battery pack is inserted along a first axis, the clamp is aligned along a second axis, and the first axis and the second axis form an oblique angle.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a handle of a test and measurement device according to an embodiment of the invention.

FIG. 2 is a front view of the handle ofFIG. 1.

FIG. 3 is a bottom view of the handle ofFIG. 1.

FIG. 4 is a perspective view of a battery pack.

FIG. 5 is an exploded view of the battery pack ofFIG. 4.

FIG. 6 is a top view of the battery pack ofFIG. 4.

FIG. 7 is a rear perspective view of a clamp meter according to an embodiment of the invention.

FIG. 8 is a right side view of the clamp meter ofFIG. 7.

FIG. 9 is a left side view of the clamp meter ofFIG. 7.

FIG. 10 is a top view of the clamp meter ofFIG. 7.

FIG. 11 is a bottom view of the clamp meter ofFIG. 7.

FIG. 12 is a front view of the clamp meter ofFIG. 7.

FIG. 13 is a rear view of the clamp meter ofFIG. 7.

FIG. 14 is a front perspective view of a secondary battery lock according to an embodiment of the invention.

FIG. 15 is a rear view of the secondary battery lock ofFIG. 14.

FIG. 16 is a top view of the secondary battery lock ofFIG. 14.

FIG. 17 is a front view of a secondary battery lock according to another embodiment of the invention.

FIG. 18 is a perspective view of a secondary battery lock according to another embodiment of the invention.

FIG. 19 is a rear perspective view of a clamp meter jaw mechanism according to an embodiment of the invention.

FIG. 20 is a top view of the clamp meter jaw mechanism ofFIG. 19.

FIG. 21 is a side view of the clamp meter jaw mechanism ofFIG. 19.

FIG. 22 is a block diagram of the clamp meter ofFIG. 7.

FIG. 23 is a rear perspective view of an infrared (“IR”) thermometer according to an embodiment of the invention.

FIG. 24 is a front view of the IR thermometer ofFIG. 23.

FIG. 25 is a right side view of the IR thermometer ofFIG. 23.

FIG. 26 is a left side view of the IR thermometer ofFIG. 23.

FIG. 27 is a rear view of the IR thermometer ofFIG. 23.

FIG. 28 is a top view of the IR thermometer ofFIG. 23.

FIG. 29 is a bottom view of the IR thermometer ofFIG. 23.

FIG. 30 illustrates a control section of the IR thermometer ofFIG. 23.

FIG. 31 is an exploded view of the IR thermometer ofFIG. 23.

FIG. 32 is a block diagram of an IR thermometer according to an embodiment of the invention.

FIG. 33 illustrates a process for operating an IR thermometer according to an embodiment of the invention.

FIG. 34 illustrates a perspective view of a wall scanner according an embodiment of the invention.

FIG. 35 illustrates a top view of the wall scanner ofFIG. 34.

FIG. 36 illustrates a front view of the wall scanner ofFIG. 34.

FIG. 37 illustrates a side view of the wall scanner ofFIG. 34.

FIG. 38 illustrates an exploded view of the wall scanner ofFIG. 34.

FIG. 39 illustrates an exploded view of a lower portion of the wall scanner ofFIG. 34.

FIG. 40 illustrates an exploded view of a side portion of the wall scanner ofFIG. 34.

FIG. 41 illustrates an exploded view of a control section and a display according to an embodiment of the invention.

FIG. 42 is a block diagram of a wall scanner according to an embodiment of the invention.

FIG. 43 illustrates a control section of a wall scanner according to an embodiment of the invention.

FIG. 44 illustrates a plurality of display screens of a wall scanner according to an embodiment of the invention.

FIG. 45 illustrates a plurality of display screens of a wall scanner in a stud scanning mode according to an embodiment of the invention.

FIG. 46 illustrates a plurality of display screens of a wall scanner in a metal scanning mode according to an embodiment of the invention.

FIG. 47 illustrates a control process for a wall scanner according to an embodiment of the invention.

DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

Test and measurement devices (e.g., wall scanners, thermometers, digital multimeters (“DMMs”), clamp meters, etc.) and other non-motorized sensing tools are generally lightweight and low-power consumption devices which are powered by one or more alkaline batteries. Removable and rechargeable batteries (e.g., nickel-cadmium (“NiCd”) or nickel-metal hydride (“NiMH”) batteries), such as those used in power tools, cannot reasonably be used with test and measurement devices because of the batteries' size and weight. However, lithium-ion battery packs enable the use of high-voltage removable and rechargeable battery packs with these non-motorized sensing tools.

As a result of the test and measurement devices receiving operational power from battery packs with lithium-based chemistries, the devices are capable of including a variety of features or functions in addition to their traditional features and functions, which increase the power demand of the devices. For example, a clamp meter can include a high-intensity LED flashlight, a non-contact voltage detector, a thermocouple, a backlighted control section or actuators, a high-resolution LCD, a color LCD, and/or an additional or remote display. Conventionally powered clamp meters (e.g., clamp meters powered by alkaline batteries) are either unable to provide the required voltage and current to power these additional features, or the operational runtime (i.e., the amount of time for which the batteries can power the clamp meter before the batteries need to be replaced or recharged) of the alkaline batteries is shortened. In contrast, the lithium-based battery packs are capable of powering the additional features of the clamp meter as well as the traditional features and functions, while maintaining an operational runtime that is comparable to or longer than a conventional clamp meter that does not include additional features. Additional test and measurement devices, such as infrared (“IR”) thermometers and wall scanners, are also able to include additional features and functions when powered by the lithium-based battery packs.

An embodiment of the invention is described with respect to a handle for a test and measurement device, such as thehandle10 illustrated inFIGS. 1, 2, and 3. Thehandle10 is a pistol-grip handle and includes anouter casing15 and a plurality of recesses. Theouter casing15 includes, for example, afirst half20 and asecond half25. The first andsecond halves20 and25 of theouter casing15 are fixedly attached to one another in, for example, a clamshell configuration. Thefirst half20 and thesecond half25 form the plurality of recesses when coupled to one another. In other embodiments, thehandle10 is molded as a single piece. Afirst recess30 includes a mating interface, such as, for example, rails or a mating groove (not shown) for slidably receiving an attachment, such as the battery pack. Asecond recess35 is configured to receive a control device, such as, for example, a trigger or a knob for controlling at least a portion of the operation of the device. In other embodiments of the invention, more or fewer recesses are included. Thehandle10 is further configured to ergonomically conform to the shape of a user's hand (right or left) such that the device can be held and operated using a single hand without the user having to divert his or her line-of-sight, as described below.

Thehandle10 is configured to offset a holding position of the device to align a display, the control device, and the operation of the device with the user's line-of-sight or afirst axis40. Thehandle10 is attached to a lower portion of a main body of the device along asecond axis45 such that thehandle10 is at an oblique angle with respect to thefirst axis40. In other embodiments, thehandle10 is approximately perpendicular to the main body. The battery pack is inserted into thefirst recess30 and along thesecond axis45 of thehandle10 to provide power to the test and measurement device.

An embodiment of a lithium-based battery pack for powering the test and measurement device is illustrated inFIGS. 4, 5, and 6. In the illustrated embodiment, thebattery pack100 includes battery cells having a lithium-based chemistry such that thebattery pack100 is over 65% lighter and 50% smaller than an equivalent nickel-cadmium (“NiCd”) battery pack. The lithium-ion battery pack100 also provides a longer operational run-time for the test and measurement device, and a longer life (e.g., number of recharge cycles) than the other non-lithium-based battery packs.

The illustratedbattery pack100 includes acasing105, anouter housing110 coupled to thecasing105, and a plurality of battery cells115 (seeFIG. 5) positioned within thecasing105. Thecasing105 is shaped and sized to fit within therecess30 in the device to connect thebattery pack100 to the device. Thecasing105 includes anend cap120 to substantially enclose thebattery cells115 within thecasing105. Theillustrated end cap120 includes twopower terminals125 configured to mate with corresponding power terminals of the device. In other embodiments, theend cap120 may includeterminals125 that extend from thebattery pack100 and are configured to be received in receptacles supported by the device. Theend cap120 also includes sense or communication terminals130 (seeFIG. 6) that are configured to mate with corresponding terminals from the device. Theterminals130 couple to a battery circuit (not shown). The battery circuit can be configured to monitor various aspects of thebattery pack100, such as pack temperature, pack and/or cell state of charge, etc. and can also be configured to send and/or receive information and/or commands to and/or from the device. In one embodiment, the battery circuit operates as illustrated and described in U.S. Pat. No. 7,157,882 entitled “METHOD AND SYSTEM FOR BATTERY PROTECTION EMPLOYING A SELECTIVELY-ACTUATED SWITCH,” issued Jan. 2, 2007, the entire contents of which are hereby incorporated by reference. In another embodiment, the battery circuit operates as illustrated and described in U.S. Pat. No. 7,589,500 entitled “METHOD AND SYSTEM FOR BATTERY PROTECTION,” issued Sep. 15, 2009, the entire contents of which are also hereby incorporated by reference.

Thecasing105 andpower terminals125 substantially enclose and cover the terminals of the device when thepack100 is positioned in therecess30. That is, thebattery pack100 functions as a cover for therecess30 and terminals of the device. Once thebattery pack100 is disconnected from the device and the casing is removed from therecess30, the battery terminals on the device are generally exposed to the surrounding environment.

Theouter housing110 is coupled to an end of the casing substantially opposite theend cap120 and surrounds a portion of thecasing105. In the illustrated construction, when thecasing105 is inserted into or positioned within the correspondingrecess30 in the device, theouter housing110 generally aligns with an outer surface of the handle. In this construction, theouter housing110 is designed to substantially follow the contours of the device to match the general shape of the handle. In such embodiments, theouter housing110 generally increases (e.g., extends) the length of thehandle10 of the test and measurement device.

In the illustrated embodiment, two actuators135 (only one of which is shown) and twotabs140 are formed in theouter housing110 of thebattery pack100. Theactuators135 and thetabs140 define a coupling mechanism for releasably securing thebattery pack100 to the device. Eachtab140 engages a corresponding recess formed in the device to secure thebattery pack100 in place. Thetabs140 are normally biased away from the casing105 (i.e., away from each other) due to the resiliency of the material forming theouter housing110. Actuating (e.g., depressing) theactuators135 moves thetabs140 toward the casing105 (i.e., toward each other) and out of engagement with the recesses such that thebattery pack100 may be pulled out of therecess30 and away from the device. The device also includes a secondary battery lock (described below) which must be released before thebattery pack100 can be removed from the device. In other embodiments, thebattery pack100 may include other suitable coupling mechanisms to releasably secure thebattery pack100 to the device, as discussed below.

As shown inFIG. 5, thebattery pack100 includes threebattery cells115 positioned within thecasing105 and electrically coupled to theterminals125. Thebattery cells115 provide operational power (e.g., DC power) to the test and measurement device. In the illustrated embodiment, thebattery cells115 are arranged in series, and eachbattery cell115 has a nominal voltage of approximately four-volts (“4.0V”), such that thebattery pack100 has a nominal voltage of approximately twelve-volts (“12V”). Thecells115 also have a capacity rating of approximately 1.4 Ah. In other embodiments, thebattery pack100 may include more orfewer battery cells115, and thecells115 can be arranged in series, parallel, or a serial and parallel combination. For example, thebattery pack100 can include a total of sixbattery cells115 in a parallel arrangement of two sets of three series-connected cells. The series-parallel combination ofbattery cells115 creates abattery pack100 having a nominal voltage of approximately 12V and a capacity rating of approximately 2.8 Ah. In other embodiments, thebattery cells115 may have different nominal voltages, such as, for example, 3.6V, 3.8V, 4.2V, etc., and/or may have different capacity ratings, such as, for example, 1.2 Ah, 1.3 Ah, 2.0 Ah, 2.4 Ah, 2.6 Ah, 3.0 Ah, etc. In other embodiments, thebattery pack100 can have a different nominal voltage, such as, for example, 10.8V, 14.4V, etc. In the illustrated embodiment, thebattery cells115 are lithium-ion battery cells having a chemistry of, for example, lithium-cobalt (“Li—Co”), lithium-manganese (“Li—Mn”), or Li—Mn spinel. In other embodiments, thebattery cells115 may have other suitable lithium or lithium-based chemistries.

Another embodiment of the invention is described with respect to aclamp meter200 as illustrated inFIGS. 7-13. Theclamp meter200 includes, among other things, thehandle10 described above, aclamp205, amain body210, an embeddeddisplay215, a plurality ofcontrol buttons220, electrical terminals or leads225, an aperture for a secondary battery lock230 (seeFIG. 12), a control device or trigger235, a jaw mechanism (seeFIG. 9), aflashlight237, and a non-contact voltage detector (not shown). Thehandle10 is also operable to receive thebattery pack100. Theclamp meter200 is operable to measure various electrical properties or characteristics of circuit elements such as wires, resistors, capacitors, and the like.

Theclamp205 is attached to afront portion240 of themain body210 along thefirst axis40 such that thehandle10 also forms an oblique angle with respect to theclamp205. Theclamp205 supports and encloses a magnetic core for measuring current flowing through an object or medium (e.g., a wire). Theclamp205 allows a user to measure, for example, the electrical current flowing through the circuit element without disconnecting the element from the corresponding circuit. When theclamp205 is opened, a conductor (e.g., a wire) is positioned within an opening defined by theclamp205 such that the magnetic core substantially surrounds the wire. When theclamp205 is closed, an alternating current flowing through the conductor induces a current in theclamp205.

Thedisplay215 is attached to arear portion245 of themain body210 along thefirst axis40. The user's line-of-sight is aligned with or parallel to thefirst axis40. In the illustrated embodiment, thedisplay215 is a liquid crystal display (“LCD”), such as a negative LCD (“NLCD”) with an electroluminescent backlight, but may alternatively be another suitable type of display. The negative LCD includes lighted symbols, such as white alphanumeric symbols, on a black background. The NCLD improves the visibility of thedisplay215 in low or poor lighting conditions, such as outdoor, dark, or dirty conditions. In some embodiments, thedisplay215 is at a first angle with respect to thefirst axis40 to improve the visibility of thedisplay215. Thedisplay215 also includes a screen timeout period which is either preprogrammed or set by the user. If the screen timeout period is reached or lapses and nocontrol buttons220 are actuated and/or no measurements are taken, thedisplay215 enters a standby or power saving mode to conserve power.

Thecontrol buttons220 are positioned proximate to thedisplay215, on thehandle10, on themain body210, or any combination thereof. The position and configuration of thebuttons220 allow theclamp meter200 to be controlled without the user having to divert his or her line-of-sight from thedisplay215 or the operation of theclamp meter200. Thecontrol buttons220 are operable to select functions and adjust settings of theclamp meter200. For example, onecontrol button220 may be actuated to zero the clamp meter, onecontrol button220 may be actuated to change the units of a displayed value (e.g., from Fahrenheit to Celsius), onecontrol button220 may be actuated to temporarily hold or save a displayed value, onecontrol button220 may be actuated to display minimum and maximum measured values, and onecontrol button220 may be actuated to display only a peak or inrush value.

Theclamp meter200 also includes positive andnegative terminals225 positioned on therear portion245 of themain body210 substantially opposite theclamp205. Theterminals225 are operable to receive electrical leads for probes (not shown), allowing a user to test other electrical characteristics or properties of a circuit. For example, theterminals225 can be used to measure AC and DC current, AC and DC voltages, resistance, and capacitance of various circuit elements. In some embodiments, theterminals225 are operable to receive a contact temperature sensor such as a thermocouple (e.g., a K-type thermocouple). The thermocouple includes two metallic elements (e.g., a hot junction and a cold junction) which provide differing output voltages. The difference between the output voltages is used to determine a contact temperature measurement. An ambient temperature sensor (not shown) such as a thermistor can be used in combination with a look-up table for cold junction compensation of the thermocouple. In some embodiments, the thermocouple is operable to detect temperatures in the range of, for example, −40° C. (−40° F.) to 400° C. (752° F.).

As shown inFIG. 10, theclamp meter200 also includes adial250 supported on an upper surface of themain body210. Thedial250 is electrically coupled to a controller and is operable to change the operating mode (i.e., the electrical characteristic being tested) of theclamp meter200. That is, actuating (e.g., rotating) thedial250 adjusts the electrical characteristic being measured by theclamp meter200. The electrical characteristics that theclamp meter200 can measure include, for example, alternating current (“AC”), direct current (“DC”), AC voltage, DC voltage, resistance, capacitance, continuity, and temperature. In addition, one position of thedial250 is an off position to interrupt current flowing from thebattery pack100 to theclamp meter200.

In some embodiments, theclamp meter200 includes a secondary battery lock or redundant locking mechanism or another suitable lockable structure which prevents a user from easily removing the battery pack. For example, in one embodiment, theclamp meter200 includes asecondary battery lock300, as shown inFIGS. 14-16. Thesecondary battery lock300 works in conjunction with the actuators and tabs of thebattery pack100, and is operable to redundantly secure thebattery pack100 to theclamp meter200. In the illustrated embodiment, thesecondary battery lock300 includes afirst end305 havingball joints310 for pivotably coupling thesecondary battery lock300 to thehandle10 of theclamp meter200. Thesecondary battery lock300 includes asecond end315 having aflange320 for mating with a rib, groove, spine, etc. of thebattery pack100. Thesecondary battery lock300 is positioned within the aperture230 (seeFIG. 12) of thehandle10, and is configured such that it is only releasable using a separate tool, such as a flat-headed screwdriver or a knife. As such, thesecondary battery lock300 must be consciously opened or brought out of engagement with thebattery pack100 before thebattery pack100 can be removed. Thesecondary battery lock300 also includes an arcuatecentral portion325 which connects thefirst end305 and thesecond end315. Thecentral portion325 is configured to conform to the contours and curvature of thehandle10. In some embodiments, thecentral portion325 is straight and does not conform to the contours of thehandle10.

FIG. 17 illustrates asecondary battery lock400 according to another embodiment. Thesecondary battery lock400 is similar to thesecondary battery lock300 described above with respect toFIGS. 14-16. However, thesecondary battery lock400 is positioned behind asurface405 or door within theaperture230 of thehandle10. In some embodiments, thesecondary battery lock400 includes a first end having, for example, ball joints for pivotably coupling thesecondary battery lock400 to the housing of the clamp meter. In other embodiments, thesecondary battery lock400 includes a cylindrical recess for receiving a rod, shaft, or pin. In such embodiments, thesecondary battery lock400 pivots about the cylindrical recess. Thesecondary battery lock400 includes a second end having a flange for mating with a rib, groove, spine, etc. of the battery pack. Thesecondary battery lock400 also includes an arcuate central portion which connects the first end and the second end. The central portion is configured to conform to the contours and curvature of thehandle10.

Thesecondary battery lock400 is contacted through akeyhole410 in thesurface405 of thehandle10. Thekeyhole410 is configured such that thesecondary battery lock400 is only releasable using a separate tool, such as a flat-headed screwdriver or a knife. The tool is inserted into thekeyhole410 to contact thesecondary battery lock400, thebattery lock400 is forced to pivot about the first end, and the battery lock disengages thebattery pack100. As such, thesecondary battery lock400 must be consciously opened or brought out of engagement with thebattery pack100 before thebattery pack100 can be removed.

FIG. 18 illustrates asecondary battery lock500 according to yet another embodiment. Thesecondary battery lock500 is similar to thesecondary battery lock300 described above with respect toFIGS. 14-16. However, thesecondary battery lock500 includes ascrew505 having afirst cam510. Thesecondary battery lock500 includes a first end515 having, for example, acylindrical recess520 for receiving a rod, shaft, or pin, and afirst flange525 or surface. In such embodiments, thesecondary battery lock500 pivots about thecylindrical recess520. In other embodiments, thesecondary battery lock500 includes ball joints for pivotably coupling the secondary battery lock to thehandle10. Thesecondary battery lock500 includes a second end530 having a second flange535 for mating with a rib, groove, spine, etc. of thebattery pack100. Thesecondary battery lock500 also includes an arcuate central portion540 which connects the first end515 and the second end530. The central portion540 is configured to conform to the contours and curvature of thehandle10. Thesecondary battery lock500 is disengaged from thebattery pack100 by turning thescrew505 using a separate tool, such as a screwdriver or a knife. Thescrew505 is accessed through a window in thehandle10 or a keyhole similar to that described above with respect toFIG. 17. As thescrew505 is turned, thefirst cam510 is rotated into engagement with thefirst flange525. Thefirst cam510 forces thefirst flange525 to rotate about thecylindrical recess520 and disengage the second flange535 from thebattery pack100. In some embodiments, thescrew505 is spring loaded such that thescrew505 is caused to close or rotate thesecondary battery lock500 into engagement with thebattery pack100 when thebattery pack100 is inserted into a thefirst recess30. Accordingly, thesecondary battery lock500 must be consciously brought out of engagement with thebattery pack100 before thebattery pack100 can be removed.

Thetrigger235 of theclamp meter200 is operable to control, for example, a jaw mechanism for opening and closing theclamp205. Thetrigger235 is also operable to turn on theLED flashlight237. In one embodiment, theclamp meter200 includes ajaw mechanism600 as illustrated inFIGS. 19-21. Thejaw mechanism600 includes thetrigger235, a conductor orswitch605, anLED flashlight circuit610, aram615, afirst spring620, asecond spring625, afirst jaw630, and asecond jaw635. In the illustrated embodiment, thejaw mechanism600 is operable to both activate anLED flashlight237 and open the first andsecond jaws630 and635. Theswitch605 is a two-stage switch. Thetrigger235 pivots about apoint640 such that a rotational motion is imparted upon theflashlight circuit610. For example, thetrigger235 is engaged a first distance to close theswitch605 and activate theLED flashlight237. As thetrigger235 is engaged, a terminal contact of theflashlight circuit610 moves in the direction opposite to the motion of thetrigger235 and approaches theswitch605. After thetrigger235 has been engaged the first distance, the terminal contact of thecircuit610 contacts theswitch605 and closes anLED flashlight circuit610. With theLED flashlight circuit610 closed, a voltage provided by thebattery pack100 is applied to the terminals of theLED flashlight237 and theLED flashlight237 is illuminated.

As thetrigger235 is engaged further, the top portion of thetrigger235 contacts theram615 and produces a linear motion toward the first andsecond jaws630 and635. Theram615 is coupled to first and second jaw latches655 and660 of the first andsecond jaws630 and635, respectively. Thefirst spring620 and thesecond spring625 are also coupled to first andsecond hooks665 and670, respectively, to provide a resilient connection between the first andsecond jaws630 and635 and themain body210. After thetrigger235 has been engaged a second distance, the top portion of the trigger forces theram615 into the first andsecond jaws630 and635. The linear motion of theram615 is converted into a rotational motion of the first andsecond jaws630 and635 about first and second jaw pivot axes675 and680, respectively. When thetrigger235 is fully engaged, theram615 is fully extended, and theclamp205 provides a maximum separation between the first andsecond jaws630 and635 to allow a wire or other conductor to be placed within theclamp205.

After the conductor has been placed within theclamp205, thetrigger235 is released to close the first andsecond jaws630 and635. If the user requires theLED flashlight237 to illuminate an area enclosed by theclamp205 or in front of theclamp meter200, thetrigger235 can be partially disengaged such that the terminal contact of theLED flashlight circuit610 remains in contact with theswitch605 to close theLED flashlight circuit610. Alternatively, thetrigger235 can be fully disengaged and theLED flashlight237 is deactivated. When the first andsecond jaws630 and635 are closed, the magnetic core within theclamp205 is closed, and an induced current can be used to measure the current in the conductor. In some embodiments, thetrigger235 is coupled to a geared mechanical actuator. In other embodiments, theclamp205 may be opened and closed electronically when thetrigger235 is engaged and disengaged, or a different mechanical jaw mechanism can be used.

Theflashlight237 can include an incandescent light bulb, a plurality of light emitting diodes, or the like. In one embodiment, theLED flashlight237 includes three high-intensity LEDs and has an output of, for example, 250 LUX at a distance of two feet. In some embodiments of the invention, the output of theLED flashlight237 is greater than 250 LUX at a distance of two feet. In some embodiments, theLED flashlight237 is integral to or detachable from theclamp meter200. In such embodiments, theflashlight237 includes a secondary power source that is charged or otherwise receives power from thebattery pack100. TheLED flashlight237 also includes a flashlight timeout period. The flashlight timeout period can have a preprogrammed value or be set by the user. If the flashlight timeout period is reached or lapses and theLED flashlight237 has not been turned off, theclamp meter200 turns off theLED flashlight237 to conserve power.

The non-contact voltage detector (“NCVD”) (not shown) is positioned at a base of theclamp205 on themain body210. A voltage sense circuit is positioned within theclamp meter200 and illuminates a voltage sense indicator, such as an LED, when it detects an AC voltage. In some embodiments, all or a portion of the voltage sense circuit is included in a clamp meter controller (described below). The voltage sense circuit is operable to detect AC voltages in the range of, for example, 90V-600V. In some embodiments, the voltage sense circuit NCVD is operable to detect AC voltages anytime the clamp meter is powered or turned on. In other embodiments, the NCVD is selectively activatable using an NCVD control button or switch. In other embodiments, the clamp meter includes a detachable non-contact voltage detector (not shown), such as that described in U.S. Pat. No. 8,193,802, issued on Jun. 5, 2012 and titled “SLIDABLY ATTACHABLE NON-CONTACT VOLTAGE DETECTOR,” the entire contents of which are hereby incorporated by reference, which is slidably attachable to the clamp meter.

FIG. 22 is a block diagram of theclamp meter200 ofFIG. 7. In addition to the components and features of theclamp meter200 described above, theclamp meter200 also includes a controller700. The controller700 receives signals from theclamp205, theNCVD705, the electrical leads orterminals225, thedial250, thecontrol buttons220, thetrigger235, and thebattery pack100. The controller700 processes and/or conditions the signals, and outputs the conditioned signals to, for example, thedisplay215 or another indication device, such as the voltage sense indicator. The clamp meter controller700 includes for example, at least one printed circuit board (“PCB”). The PCB is populated with a plurality of electrical and electronic components which provide operational control and protection to the clamp meter. In some embodiments, the PCB includes a control or processing unit such as a microprocessor, a microcontroller, or the like. In some embodiments, the controller700 includes, for example, the processing unit, a memory, and a bus. The bus connects various components of the controller700 including the memory to the processing unit. The memory includes, in some embodiments, read only memory (“ROM”) and random access memory (“RAM”). The controller700 also includes an input/output system that includes routines for transferring information between components within the controller700. Software included in the implementation of the clamp meter is stored in the ROM or RAM of the controller700. The software includes, for example, firmware applications and other executable instructions. In other embodiments, the controller700 can include additional, fewer, or different components.

The PCB also includes, for example, a plurality of additional passive and active components such as resistors, capacitors, inductors, integrated circuits, and amplifiers. These components are arranged and connected to provide a plurality of electrical functions to the PCB including, among other things, filtering, signal conditioning, and voltage regulation. For descriptive purposes, the PCB and the electrical components populated on the PCB are collectively referred to herein as “the controller”700. Thedisplay215 receives the processed and conditioned signals from the controller700 and displays a value (e.g., a number) corresponding to the measured current, or an indication of a control parameter of the clamp meter200 (e.g., sensing mode).

In some embodiments, a battery pack controller (not shown) provides information to the clamp meter controller700 related to a battery pack temperature or voltage level. The clamp meter controller700 and the battery pack also include low voltage monitors and state-of-charge monitors. The monitors are used by the clamp meter controller700 or the battery pack controller to determine whether the battery pack is experiencing a low voltage condition, which may prevent proper operation of theclamp meter200, or if the battery pack is in a state-of-charge that makes thebattery pack100 susceptible to being damaged. If such a low voltage condition or state-of-charge exists, theclamp meter200 is shut down or thebattery pack100 is otherwise prevented from further discharging current to prevent thebattery pack100 from becoming further depleted.

Another embodiment of the invention is described with respect to an infrared (“IR”) thermometer.FIGS. 23-29 illustrate anIR thermometer810 that includes, among other things, ahandle815, amain body820, an embeddeddisplay825, a control device or trigger830, acontrol section835, agrip portion840, and a high-voltage removable and rechargeable battery pack (described below). Thehandle815 is substantially similar to thehandle10 described above with respect toFIGS. 1-3. The handle portion includes a recess that is adapted to receive thebattery pack100 described above with respect toFIGS. 4-6.

Thedisplay825 is attached to a rear portion of themain body820 along thefirst axis850. The user's line-of-sight is aligned with or parallel to afirst axis850. In the illustrated embodiment, thedisplay825 is a liquid crystal display (“LCD”), such as a negative LCD (“NLCD”) with an electroluminescent backlight, but may alternatively be another suitable type of display. The negative LCD includes lighted symbols, such as white alphanumeric symbols, on a black background. The NCLD improves the visibility of thedisplay825 in low or poor lighting conditions, such as outdoor, dark, or dirty conditions. In some embodiments, thedisplay825 is at an offset angle with respect to thefirst axis850 to improve the visibility of thedisplay825. Thedisplay825 also includes a screen timeout period which is either preprogrammed or set by the user. If the screen timeout period is reached or lapses and no buttons in thecontrol section835 are actuated and/or no measurements are taken, thedisplay825 enters a standby or power saving mode to conserve power.

Thecontrol section835 is illustrated inFIG. 30. Thecontrol section835 is positioned proximate to thedisplay825 and includes a plurality of control buttons. The position and configuration of the control buttons allow thethermometer810 to be controlled without the user having to divert his or her line-of-sight fromdisplay825 or the operation of thethermometer810. For example, in the illustrated embodiment, thecontrol section835 is positioned below thedisplay825. Thecontrol section835 includes amode button860, an upbutton865, adown button870, asettings button875, a log savebutton880, analarm button885, and aflashlight button890. Themode button860 is actuated to select an operational mode from, for example, a menu or a predetermined set of operational modes. For example, themode button860 allows a user to scroll through a plurality of operational modes, such as an average temperature mode, a maximum temperature mode, a minimum temperature mode, a humidity mode, a dew point mode, a wet bulb mode, and a contact temperature mode. In some embodiments, themode button860 is repeatedly selected to cycle through the operational modes of thethermometer810. In other embodiments, themode button860 is pressed once, and the up and downbuttons65 and870 are used to scroll throughthermometer810 modes. The selected operational mode determines the information that is displayed on thedisplay825. As such, in some embodiments, thethermometer810 is a menu-driven device. In some embodiments, thethermometer810 also includes one or more LEDs for providing an indication to the user of the status or operational mode of thethermometer810, the battery pack, or both.

Additional control buttons can be located on thehandle815 and/or themain body820. For example, an electronictrigger lock button895 is located on thehandle815 and enables thethermometer810 to take a continuous non-contact temperature reading without thetrigger830 being engaged. In some embodiments, thethermometer810 takes the non-contact temperature reading until the user engages the trigger830 a second time. In other embodiments, the continuous reading is taken until thetrigger lock button895 is deactivated, or a predetermined time limit (e.g., 20 minutes) has elapsed.

If thethermometer810 is operating in the average temperature mode, an indication that thethermometer810 is operating in the average temperature mode is displayed on thedisplay825. In one embodiment, the letters “AVG” are displayed. When operating in the average temperature mode, the average temperature during the course of a single temperature reading (e.g., the time during which thetrigger830 is pressed) is also displayed on thedisplay825. If thethermometer810 is operating in the maximum temperature mode, an indication that thethermometer810 is operating in the maximum temperature mode is displayed on thedisplay825. In one embodiment, the letters “MAX” are displayed. When operating in the maximum temperature mode, the maximum temperature reading during the course of a single temperature reading is also displayed. If thethermometer810 is operating in the minimum temperature mode, an indication that thethermometer810 is operating in the minimum temperature mode is displayed on thedisplay825. In one embodiment, the letters “MIN” are displayed. When operating in the minimum temperature mode, the minimum temperature reading during the course of a single temperature reading is also displayed on thedisplay825. If thethermometer810 is operating in the humidity mode, an indication that thethermometer810 is operating in the humidity mode is displayed on thedisplay825. In one embodiment, the letters “HUM” are displayed, as well as an indication that a relative humidity measurement is being displayed (e.g., “RH %”). When operating in the humidity mode, a three-digit relative humidity (e.g., 96.3) is displayed. If thethermometer810 is operating in the dew point mode, an indication that thethermometer810 is operating in the dew point mode is displayed on thedisplay825. In one embodiment, the letters “DEW” and a calculated dew point are displayed. If thethermometer810 is in the wet bulb mode, an indication that thethermometer810 is operating in the wet bulb mode is displayed. In one embodiment, the letters “WET” and a wet bulb calculation are displayed. If thethermometer810 is operating in the contact temperature mode, an indication that thethermometer810 is operating in the contact temperature mode is displayed. In one embodiment, the letters “CON” and a contact temperature measurement are displayed on thedisplay825.

Thesettings button875 is operable to set or modify various thresholds and functions of thethermometer810. For example, thesettings button875 is actuated to scroll through the thresholds and functions which the user can control. For example, thesettings button875 allows a user to set a high temperature alarm threshold, a low temperature alarm threshold, a log reading, an emissivity, and temperature measurement units (e.g., Fahrenheit or Celsius), and turn a laser (seeFIG. 31) on and off. In some embodiments, thesettings button875 is repeatedly actuated to cycle through the thresholds and functions. In other embodiments, thesettings button875 is actuated once, and the up and downbuttons865 and870 are used to scroll through thermometer thresholds and functions.

When setting the high temperature alarm threshold, the user actuates thesettings button875 until the letters “HI” appear on thedisplay825. The user adjusts the high temperature alarm threshold using the up and downbuttons865 and870. The alarm is activated when the non-contact temperature reading is above the high temperature alarm threshold. When setting the low temperature alarm threshold, the user actuates thesettings button875 until the letters “LOW” appear on thedisplay825. The user adjusts the low temperature alarm threshold using the up and downbuttons865 and870. The alarm is activated when the non-contact temperature reading is below the low temperature alarm threshold. The alarm is toggled on and off using thealarm button885. When setting a log value, the user actuates thesettings button875 until the letters “LOG” appear on thedisplay825. Thethermometer810 also displays a number (e.g., between 1 and 20) which indicates a log value memory location. For example, if a log value was previously saved to a log value memory location, the previously saved log value is displayed. The user can scroll through the saved log values using the up and downbuttons865 and870. The user can overwrite the previously saved log value by actuating the log savebutton880 when a particular log value memory location is displayed. The user sets the emissivity of thethermometer810 by actuating thesettings button875 until the symbol, ε, is displayed. The user adjusts the emissivity level using the up and downbuttons865 and870. The user toggles the laser on and off by actuating thesettings button875 until a laser symbol (e.g., a class two laser safety symbol) is displayed, and using the up and downbuttons865 and870 to selectively activate and deactivate the laser.

FIG. 31 illustrates an exploded view of theIR thermometer810. Thethermometer810 includes, among other things, thetrigger lock button895, anIR temperature sensor900, a contacttemperature sensor port905, ahumidity sensor910, abuzzer920, anLED flashlight925, a laser module935, aconvex lens940, acylindrical aluminum tube945, and anLCD assembly950. Theflashlight925 is toggled on and off using theflashlight button890 in thecontrol section835. Theflashlight925 can include an incandescent light bulb, a plurality of light emitting diodes, or the like. In one embodiment, theLED flashlight925 includes three high-intensity LEDs and has an output of, for example, 250 LUX at a distance of two feet. In some embodiments of the invention, the output of theLED flashlight925 is greater than 250 LUX at a distance of two feet. In some embodiments, theLED flashlight925 is integral to or detachable from thethermometer810. In such embodiments, theflashlight925 includes a secondary power source that is charged or otherwise receives power from the battery pack. TheLED flashlight925 also includes a flashlight timeout period. The flashlight timeout period can have a preprogrammed value or be set by the user. If the flashlight timeout period is reached or lapses and theLED flashlight925 has not been turned off, thethermometer810 turns off theLED flashlight925 to conserve power.

FIG. 32 is a block diagram of theIR thermometer810. Thethermometer810 includes athermometer controller1000, theIR temperature sensor900, the contacttemperature sensor port905, thehumidity sensor910, anambient temperature sensor1005, thecontrol section835, and thedisplay825. Thecontroller1000 includes a plurality ofdifferential amplifiers1010, a plurality of analog-to-digital converters (“ADCs”)1015, aprocessing module1020, anIR temperature output1025, acontact temperature output1030, ahumidity output1035, anambient temperature output1040, amemory module1045, an IRtemperature compensation module1050, a contacttemperature compensation module1055, and ahumidity compensation module1060. In some embodiments, theADCs1015 are 24-bit high precision delta-sigma ADCs. Thethermometer controller1000 also includes for example, at least one printed circuit board (“PCB”). The PCB is populated with a plurality of electrical and electronic components which provide power, operational control, and protection to thethermometer810. In some embodiments, the PCB includes theprocessing module1020 which is, for example, a microprocessor. Thecontroller1000 also includes a bus for connecting the various components and modules located within or connected to thecontroller1000. Thememory module1045 includes, in some embodiments, read only memory (“ROM”), such as electronically erasable programmable ROM (“EEPROM”), and random access memory (“RAM”). Thecontroller1000 also includes an input/output system that includes routines for transferring information between components and modules within thecontroller1000. Software included in the implementation of thethermometer810 is stored in the ROM or RAM of thecontroller1000. The software includes, for example, firmware applications and other executable instructions. The IRtemperature compensation module1050 and the contacttemperature compensation module1055 use output signals from thehumidity sensor910 orambient temperature sensor1005 to compensate temperature measurements and generate a compensated IR temperature ouput and a compensated contact temperature output. Thehumidity compensation module1060 uses an output from the ambient temperature sensor to compensate humidity measurements and generate compensated humidity outputs. In other embodiments, thecontroller1000 can include additional, fewer, or different components.

The PCB also includes, for example, a plurality of additional passive and active components such as resistors, capacitors, inductors, integrated circuits, and amplifiers. These components are arranged and connected to provide a plurality of electrical functions to the PCB including, among other things, sensing, filtering, signal conditioning, and voltage regulation. For descriptive purposes, the PCB and the electrical components populated on the PCB are collectively referred to herein as “the controller”1000. Thecontroller1000 receives signals from theIR temperature sensor900, the contacttemperature sensor port905, thehumidity sensor910, and theambient temperature sensor1005; processes or conditions the signals; and transmits the processed and conditioned signals to thedisplay825. In some embodiments, theIR temperature sensor900, the contacttemperature sensor port905, and thehumidity sensor910 are calibrated or recalibrated using the ambient temperature signal. Thedisplay825 receives the processed and conditioned signals and displays an indication of an IR temperature measurement, a contact temperature measurement, a humidity, a dew point, or the like to the user.

In some embodiments, a battery pack controller (not shown) provides information to thethermometer controller1000 related to a battery pack temperature or voltage level. Thethermometer controller1000 and the battery pack also include low voltage monitors and state-of-charge monitors. The monitors are used by thethermometer controller1000 or the battery pack controller to determine whether thebattery pack100 is experiencing a low voltage condition, which may prevent proper operation of thethermometer810, or if the battery pack is in a state-of-charge that makes the battery pack susceptible to being damaged. If such a low voltage condition or state-of-charge exists, thethermometer810 is shut down or thebattery pack100 is otherwise prevented from further discharging current to prevent the battery pack from becoming further depleted.

TheIR temperature sensor900 is, for example, a thermopile. The thermopile includes a plurality of thermoelements (e.g., thermocouples) connected in series to form a sensing area or detector, and the sensing area is covered with an IR-absorbing material. A lens focuses infrared energy onto the detector, and the thermopile outputs a signal which is directly proportional to the power of the infrared radiation incident upon the detector. In some embodiments, theIR temperature sensor900 is operable to sense temperatures in the range of, for example, −30° C. (−22° F.) to 800° C. (1472° F.). The contacttemperature sensor port905 is, for example, a thermocouple port and is operable to receive a thermocouple, such as a K-type thermocouple. The combination of the thermocouple and the thermocouple port are referred to herein as thethermocouple905. Thethermocouple905 includes two metallic elements (e.g., a hot junction and a cold junction) which provide differing output voltages. The difference between the output voltages is used to determine a contact temperature measurement. The ambient temperature sensor1005 (e.g., a thermistor) is used in combination with a look-up table for cold junction compensation of thethermocouple905. In some embodiments, thethermocouple905 is operable to detect temperatures in the range of, for example, −40° C. (−40° F.) to 550° C. (1022° F.). The thermocouple may be used independently of the temperature sensor. As such, an output of thethermocouple905 is not used to compensate or otherwise modify an output of the thermopile. The thermopile is operable to sense a first temperature of a first area in a non-contact manner, and thethermocouple905 is operable to sense a second temperature of a second area in a contact manner. In some embodiments, the first area and the second are located on the same object or surface, and thethermocouple905 can be used in conjunction with theIR temperature sensor900 to provide, for example, both contact and non-contact temperature measurements of an object. In other embodiments, the first area is located on a first object, and the second area is located on a second object.

Thehumidity sensor910 provides a signal to thecontroller1000 that is indicative of the humidity in the environment surrounding thethermometer810. Thehumidity sensor910 is for example, a resistive hygrometer which uses a polymer membrane which has a conductivity that varies with the amount of water it absorbs. Thehumidity sensor910 is used for calibrating theIR temperature sensor900 and for compensating measurements made using theIR temperature sensor900 and thethermocouple905. In some embodiments, the humidity is displayed on thedisplay825.

Thethermometer810 also includes a distance-to-spot ratio (“D:S”). The D:S ratio is a ratio of a distance to an object and a diameter of a temperature measurement area (i.e., a spot size). For example, if the D:S is 20:1, theIR temperature sensor900 averages the temperature of an object twenty feet away over an area with a one-foot diameter. The farther theIR temperature sensor900 is from the object, the larger the spot size. In some embodiments, theIR temperature sensor900 includes settings for measuring the temperature of both reflective and non-reflective surfaces.

In some embodiments, thethermometer810 also includes a distance meter (not shown). The distance meter is, for example, a laser distance meter. The distance meter uses a time-of-flight of a light pulse or an ultrasonic wave to determine a distance to the object. The distance meter measures the time-of-flight required for the light pulse or the ultrasonic wave to travel to the object and back. Based on the time-of-flight and a known speed of light (or sound), the distance to the object is calculated. In other embodiments of the invention, different techniques are used to determine the distance to the object such as a multiple frequency phase-shift technique.

The spot size is calculated using the D:S ratio of theIR temperature sensor900 and a distance measurement from the distance meter. For example, the distance meter and theIR temperature sensor900 are aligned along an axis such that the distance meter and the temperature sensor are approximately the same distance from the object. The distance meter uses a single beam of light to determine the distance from thethermometer810 to the object. Thethermometer810 uses the distance measurement from the distance meter and the D:S ratio to calculate the diameter of a measurement area on the object. Thethermometer810 then displays, for example, a numerical representation of the spot size, an area of the spot, or both. In other embodiments, a visual representation of the measurement area and/or the spot size is displayed.

FIG. 33 illustrates aprocess1100 for taking a temperature measurement using thethermometer810. Thethermometer810 first determines whether thebattery pack100 is experiencing a low-voltage condition (step1105). If thebattery pack100 is in a low-voltage condition, a low-battery warning is initiated (step1110). In some embodiments, the low-battery warning is displayed on thedisplay825. In other embodiments, an LED is lighted or a buzzer is sounded to provide the low-battery warning. If no low-voltage condition exists, thethermometer810 is operable to make temperature measurements. A default operational and display mode for thethermometer810 is the non-contact temperature measurement mode. To take an IR temperature measurement (step1115), the user engages thetrigger830. Temperature measurements are taken as long as thetrigger830 is engaged. Alternatively, if the electronictrigger lock button895 is engaged, a continuous temperature measurement can be taken without continuously engaging thetrigger830. Thethermometer810 then determines whether athermocouple905 is present (step1120). If athermocouple905 is present, a contact temperature measurement is taken (step1125) and the relative humidity is measured using the humidity sensor910 (step1130). If nothermocouple905 is present, thethermometer810 measures the relative humidity using the humidity sensor910 (step1130). Thethermometer810 then determines whether the measured IR temperature is greater than the high-temperature alarm threshold or below the low temperature alarm threshold (step1135). If the measured IR temperature is outside of the high and low threshold values, a temperature range warning is initiated (step1140). In some embodiments, the temperature range warning is displayed on thedisplay825. In other embodiments, an LED is lighted or a buzzer is sounded to provide the temperature range warning. If the measured IR temperature is not greater than the high temperature alarm threshold or less than the low temperature alarm threshold, the measured temperature is displayed on the display825 (step1145).

Another embodiment of the invention is described with respect to a wall scanner that is capable of detecting a plurality of objects hidden behind a plurality of different surfaces. The wall scanner includes a housing, a plurality of sensors, a display, a control section, and a plurality of wheels. The housing includes a body portion and a handle portion similar to thehandle10 described above with respect toFIGS. 1-3. The handle portion includes a recess that is adapted to receive thebattery pack100 described above with respect toFIGS. 4-6.

FIGS. 34-41 illustrate thewall scanner1205 and housing1210 according to an embodiment of the invention. Ahandle portion1215 of the wall scanner housing1210 includes a battery pack recess1220 (seeFIG. 38) adapted to receive thebattery pack100. Thebattery pack recess1220 includes a plurality of terminals (shown as1345 inFIG. 40) for electrically connecting thebattery pack100 to thewall scanner1205. Additionally, thehandle portion1215 includes a plurality of recessedgripping portions1235 that provide additional grip to a user.

Thehandle portion1215 and thebattery pack100 define afirst axis1241 of thewall scanner1205. Thehandle portion1215 is coupled to and extends from thebody portion1240 of thewall scanner1205 such that arecess1245 is formed between thebody portion1240 and thehandle portion1215. The extension of thehandle portion1215 from thebody portion1240 allows thewall scanner1205 to receive thebattery pack100. In some embodiments, therecess1245 between thehandle portion1215 and thebody portion1240 is closed by first and second connectingportions1250 and1255. In other embodiments, therecess1245 is open and includes a single connecting portion. Therecess1245 defines a space for accommodating the fingers of a user while the user is holding thewall scanner1205.

Thehandle portion1215 extends approximately half the length of the housing1210 and is approximately parallel to thebody portion1240 and adisplay1260. In one embodiment, thefirst axis1241 is parallel to asecond axis1243 which extends through a center of thebody portion1240. In other embodiments, thefirst axis1241 is not parallel to thesecond axis1243, and thefirst axis1241 intersects thesecond axis1243 at a point a distance, d, away from thewall scanner1205. Thedisplay1260 is positioned on thebody portion1240 such that thedisplay1260 is not blocked by the user's hand when thewall scanner1205 is being gripped. Thecontrol section1265 is provided on the first connectingportion1250 between thebody portion1240 and thehandle portion1215 of thewall scanner1205. Thecontrol section1265 is positioned at an oblique angle with respect to thebody portion1240 of the housing such that the buttons or switches (described below) within thecontrol section1265 can be activated by the user using the same hand with which the user is gripping thewall scanner1205. In some embodiments, thewall scanner1205 also includes one or more LEDs for providing an indication to the user of the status of thewall scanner1205, thebattery pack100, or both. Thewheels1270 are rotatably coupled to the housing1210 to facilitate movement of thewall scanner1205 along a surface. In the illustrated embodiment, thewheels1270 are idle wheels, but may alternatively be driven wheels that are powered by thebattery pack100.

FIG. 38 illustrates an exploded view of thewall scanner1205 shown inFIGS. 34-41. Thewall scanner1205 includes abase housing assembly1300, right and lefthousing assemblies1305 and1310, apanel assembly1315, and thebattery pack100. An exploded view of thebase housing assembly1300 is shown inFIG. 39. Thebase housing assembly1300 includes a main printed circuit board assembly (“PCB”)1320, asensor board1325 which includes plate sensors for sensing studs, a D-coil sensor1330 for sensing metal, abase1335, and thewheels1270. An exploded view of theright housing assembly1305 is shown inFIG. 40. Theleft housing assembly1310 is similar to theright housing assembly1305 and is not described in detail. Theright housing assembly1305 includescontact plate terminals1345, abattery contact PCB1350, a right half of thehousing1355, anindicator lens1360, and anLED1365. An exploded view of thepanel assembly1315 is shown inFIG. 41. Thepanel assembly1315 includes akeypad1370, akey holder1375, arubber key1380, alight guide1385, akey PCB1390, akey panel1395, anLCD lens1400, and anLCD assembly1405.

FIG. 42 is a block diagram of awall scanner1205 according to an embodiment of the invention. Thewall scanner1205 includes amain system module1415, thestud sensor1325, the D-coil sensor1330, and thedisplay1260. Themain system module1415 includes, among other things, awall scanner controller1420, asignal conditioning module1425, apeak detection module1430, and an analog-to-digital conversion module1435. Thedisplay1260 is, for example, a 128×64 dot matrix liquid crystal display (“LCD”) or negative LCD (“NLCD”). Thewall scanner controller1420 includes, for example, a PCB such asPCB1320 shown inFIG. 39. ThePCB1320 is populated with a plurality of electrical and electronic components which provide operational control and protection to thewall scanner1205. In some embodiments, thePCB1320 includes a control or processing unit such as a microprocessor, a microcontroller, or the like. In some embodiments, thecontroller1420 includes, for example, the processing unit, a memory, and a bus. The bus connects various components of thecontroller1420 including the memory to the processing unit. The memory includes, in many instances, read only memory (“ROM”) and random access memory (“RAM”). Thecontroller1420 also includes an input/output system that includes routines for transferring information between components within thecontroller1420. Software included in the implementation of thewall scanner1205 is stored in the ROM or RAM of thecontroller1420. The software includes, for example, firmware applications and other executable instructions. In other embodiments, the controller420 can include additional, fewer, or different components.

ThePCB1320 also includes, for example, a plurality of additional passive and active components such as resistors, capacitors, inductors, integrated circuits, and amplifiers. These components are arranged and connected to provide a plurality of electrical functions to thePCB1320 including, among other things, filtering, signal conditioning, and voltage regulation. For descriptive purposes, thePCB1320 and the electrical components populated on thePCB1320 are collectively referred to herein as “the controller”1420. Thecontroller1420 receives signals from the sensors within the wall scanner, conditions and processes the signals, and transmits processed and conditioned signals to thedisplay1260. Thedisplay1260 receives the processed and conditioned signals and displays an indication of a sensed characteristic of an object hidden behind a surface. Thesignal conditioning module1425 provides signals to and receives signals from thestud sensor1325, as described below; thepeak detection module1430 receives signals from and sends signals to the D-coil sensor1330, as described below; and the analog-to-digital conversion module1435 provides the conversion necessary for thecontroller1420 to interpret analog signals from the D-coil sensor1330.

In some embodiments, a battery pack controller (not shown) can provide information to thewall scanner controller1420 related to a battery pack temperature or voltage level. Thewall scanner controller1420 and the battery pack controller also include low voltage monitors and state-of-charge monitors. The monitors are used by thewall scanner controller1420 or the battery pack controller to determine whether thebattery pack100 is experiencing a low voltage condition which may prevent proper operation of thewall scanner1205, or if thebattery pack100 is in a state-of-charge that makes thebattery pack100 susceptible to being damaged. If such a low voltage condition or state-of-charge exists, thewall scanner1205 is shut down or thebattery pack100 is otherwise prevented from further discharging current to prevent thebattery pack100 from becoming further depleted.

Thewall scanner1205 is operable to detect the presence of a stud, such as a wood stud or metal joists within residential, commercial, and industrial structures using thestud sensor1325. The wooden studs or metal joists can be detected when hidden behind surfaces composed of, for example, plaster, non-metallic wall materials, wooden panels, wall board, and the like. Thestud sensor1325 includes a sensor circuit with a pair of sensors. Each sensor includes a coplanarprimary plate1440A with a single side coplanar plate1440B arranged between the primary plates. The presence and location of the stud is then determined in a manner similar to that described in U.S. Pat. No. 7,504,817, titled “STUD SENSOR,” issued on Mar. 17, 2009, the entire contents of which are hereby incorporated by reference.

Thewall scanner1205 is also configured to operate in a metal scanning mode. The metal scanning mode is operable to detect both ferrous (i.e., iron based) and non-ferrous (e.g., copper) metals within residential, commercial, and industrial structures. While in the metal scanning mode, thewall scanner1205 can detect metal (e.g., rebar, metal conduit, copper piping, etc.) behind surfaces composed of wall board, tile, plaster, brick, or the like. Thewall scanner1205 can also detect metal within walls composed of concrete, masonry, wood, brick, or the like. In some embodiments, thewall scanner1205 is operable to sense metal to a depth of, for example, six inches.

The D-coil sensor1330 illustrated inFIG. 39 uses an inductively coupled sensor that includes overlapping D-shaped transmitter andreceiver coils1445A and1445B. When the D-coil sensor1330 detects a metallic object, thesensor1330 outputs a signal to thecontroller1420 indicating the location of the object. Thewall scanner1205 detects the presence of metal in a manner similar to that described in U.S. Pat. No. 7,977,938, titled “DEVICE AND METHOD OF DETECTING FERRITE AND NON-FERRITE OBJECTS,” issued Jul. 12, 2011, the entire contents of which are hereby incorporated by reference.

Thewall scanner1205 is also configured to detect the presence of “live” (i.e., energized) electrical wiring behind a surface. In some embodiments, thewall scanner1205 includes an AC detection circuit such as that described in U.S. Pat. No. 6,894,508, titled “APPARATUS AND METHOD FOR LOCATING OBJECTS BEHIND A WALL LINING,” the entire contents of which are hereby incorporated by reference. In other embodiments, thewall scanner1205 includes a detachable non-contact voltage detector (not shown), such as that described in co-pending U.S. Pat. No. 8,193,802 entitled “SLIDABLY ATTACHABLE NON-CONTACT VOLTAGE DETECTOR,” issued Jun. 5, 2012, the entire contents of which were previously incorporated by reference, which is slidably attachable to the housing1210 of thewall scanner1205. Thewall scanner1205 includes theLED1365 for indicating the detection of an AC voltage. TheLED1365 can be located at a first end of thewall scanner1205, such as the end opposite the battery pack100 (as shown inFIG. 40), on thedisplay1260, or both. Thewall scanner1205 is operable to sense the presence of AC voltages regardless of the operational mode of the wall scanner1205 (e.g., metal sensing mode or stud sensing mode), and thewall scanner1205 does not need to be calibrated to detect the presence of AC voltages.

FIG. 43 illustrates thecontrol section1265 of thewall scanner1205. Thecontrol section1265 is positioned between thedisplay1260 and thehandle portion1215 along thefirst axis1241. Thecontrol section1265 includes buttons, switches, or other actuation devices for controlling the function and operation of thewall scanner1205. In some embodiments, thecontrol section1265 includes a metalsensing mode button1500, a studsensing mode button1505, amenu button1510, apower button1515, and acalibration button1520. In other embodiments, thecontrol section1265 includes additional buttons or switches for controlling additional or different features or functions of thewall scanner1205. One or more of the buttons included in thecontrol section1265 may have multiple functions such as selecting an operational mode and enabling a user to scroll through menu options on thedisplay1260. In the illustrated embodiment of thecontrol section1265, the buttons are arranged in a circular manner. In other embodiments, the buttons in thecontrol section1265 can be arranged in a variety of different configurations, such as a grid or an array. In various embodiments of thecontrol section1265, the buttons are configured such that a user can access and select each button using a single hand (e.g., the same hand the user is using to grip the handle portion of the wall scanner).

Thedisplay1260 is symmetrically aligned along thefirst axis1241 defined by thehandle portion1215 and thebattery pack100. Thedisplay1260 is configured to display a plurality of status indications related to the operation of thewall scanner1205. For example, thedisplay1260 can display, among other things, the operational mode of thewall scanner1205, the location of an object hidden behind the surface in real-time, the depth of an object hidden behind the surface, whether an object hidden behind the surface is ferrous or non-ferrous, battery pack power level, and an indication of whether sound (i.e., audible indication) is turned on or off.FIGS. 44-46 illustrate embodiments of wall scanner status indications that thedisplay1260 is configured to display.

Thecontroller1420 receives signals from the sensors, processes or conditions the signals, and transmits the conditioned signals to thedisplay1260, as described above. Thedisplay1260 receives the conditioned signals and displays an image, a value (e.g., a distance, coordinates, etc.), an alert relating to the detected object, test results, measurement values, properties of the wall scanner, etc. Thedisplay1260 includes lighted symbols, such as white alphanumeric symbols, on a black background. Thedisplay1260 improves the visibility of the display in low or poor lighting conditions, such as outdoor, dark, or dirty conditions. Additionally or alternatively, thewall scanner1205 can include a remote display (not shown) that can be attachable to or detachable from thewall scanner1205 to provide the user with a remote display of the detection and/or position of a stud, or the operation of thewall scanner1205. Thewall scanner1205 can include a transmitter and a receiver for communicating with the remote display. In some embodiments, the remote display is configured to display the same information as thedisplay1260.

The user can access a menu (screen1600) on thedisplay1260 by activating buttons in thecontrol section1265. From the menu, a list of options relating to various settings of thewall scanner1205 is displayed on thedisplay1260. The user is able to select between English and metric units for displaying the depth or location of an object (screen1605). The user can also select whether sound is activated (screen1610). When sound is activated, thewall scanner1205 produces, for example, a beep or a series of beeps to indicate the presence or depth of an object hidden behind a surface. In other embodiments, the menu is operable to control additional functions such as display screen brightness, turning a backlight on and off, controlling the operation of a remote display, and adjusting wall scanner sensitivities. As such, thewall scanner1205 is a menu-driven device.

Thedisplay1260 also provides instructions to the user for calibrating thewall scanner1205 after power-up. When thewall scanner1205 is operating in the stud sensing mode, the user is prompted to place thewall scanner1205 on the surface to be scanned and activate the calibration button1520 (screen1615). Thedisplay1260 then indicates to the user that thewall scanner1205 is being calibrated (screen1620). The user can, if desired, manually change the sensitivity (e.g., scan depth) of thewall scanner1205. For example, in one embodiment, a default depth setting of 0.5 inches is set for thewall scanner1205 when in the stud sensing mode. To change the scanning depth, the user activates thecalibration button1520 while thewall scanner1205 is calibrating. Activating the calibration button1520 a second time changes the scanning depth from 0.5 inches to 1.0 inches. Activating the calibration button1520 a third time changes the scanning depth from 1.0 inches to 1.5 inches. If the calibration button is activated a fourth time, the scanning depth cycles back to 0.5 in. In other embodiments, thewall scanner1205 is configured with different scanning depths and sensitivities. If an error occurs during calibration, the user is prompted with an error message, such as that shown inscreen1625.

After calibration, thedisplay1260 indicates when thewall scanner1205 is scanning for a stud (screen1630). Thedisplay1260 is configured to display the location of a detected stud in real-time as thewall scanner1205 is passing over the stud. For example, when thewall scanner1205 is moving from left to right across a surface and a stud is detected, the stud is identified by a partially illuminated portion of the display1260 (e.g., the stud is represented by a combination of illuminated pixels and non-illuminated pixels). The illuminated pixels form a plurality of lines such as horizontal lines, vertical lines, diagonal lines, or any combination thereof which are separated by non-illuminated pixels or lines. Thedisplay1260 also includes a visual and/or linguistic identification of the edge of the stud (e.g., an arrow and/or the word “edge” displayed on the wall scanner display), as shown inscreen1635. Thedisplay1260 can also display both edges of a stud if the width of the stud is not greater than the width of thedisplay1260. In such an instance, each edge is identified by an arrow and/or a linguistic identification, and the stud is represented by a combination of illuminated and non-illuminated portions (screen1640). Thewall scanner1205 includes similar visual representations of a stud's location in real-time when the wall scanner is moving from the right to the left (screen1645).

When thewall scanner1205 is operating in the metal sensing mode, the user is prompted to hold thewall scanner1205 off of the surface to be scanned in order for thewall scanner1205 to be properly calibrated (screen1650). Similar to the stud sensing mode, thewall scanner1205 provides an indication on the display that thewall scanner1205 is being calibrated (screen1655). If an error occurs during calibration, the user is prompted with an error message, such as that shown inscreen1660. After calibration, thedisplay1260 indicates when thewall scanner1205 is scanning for metal (screen1665). If thewall scanner1205 detects the presence of metal, the user is prompted visually or audibly that metal has been detected (screen1670). Thedisplay1260 then provides the user with an indication of whether the detected metal is ferrous or non-ferrous, a numerical indication of the depth of the detected object, and a visual indication of the depth of the object (screen1675). In some embodiments of the invention, thedisplay1260 can also provide a symbol to indicate the nearest distance to a detected metal object (screen1680).

Aprocess1700 for the general operation of thewall scanner1205 is illustrated inFIG. 47. After thewall scanner1205 is powered up (step1705), the default sensing mode for thewall scanner1205 is the metal sensing mode. To use the wall scanner in the metal sensing mode, the user activates thecalibration button1520 from the control section1265 (step1710). If thewall scanner1205 calibrates successfully (step1715), thewall scanner1205 is ready to detect metal objects hidden behind a surface (step1720). If thewall scanner1205 does not calibrate correctly, a calibration error is displayed (step1725), and thewall scanner1205 waits for a user to change sensing modes or activate thecalibration button1520 again (step1730). In some embodiments, if a user selects the stud sensing mode (step1735), thewall scanner1205 calibrates automatically. In other embodiments, the user must activate thecalibration button1520. If the calibration is successful (step1740), thewall scanner1205 is ready to detect studs hidden behind a surface (step1745). If the calibration is not successful, a calibration error is displayed (step1725), and thewall scanner1205 waits for the user to change sensing modes or activate thecalibration button1520 again (step1730). Followingsteps1720 and1745, thewall scanner1205 also waits for the user to change sensing modes or recalibrate the wall scanner1205 (step1730). Alternatively, the user can activate themenu button1510 from the control section1265 (step1750) to set up wall scanner tools (step1755) such as selecting display units and turning sound on and off. To exit the tools setup, the user activates the menu button1510 a second time (step1760).

Thus, the invention provides, among other things, a clamp meter configured to receive a removable and rechargeable battery pack. The clamp meter includes a main body having a first axis, a handle, a clamp, a trigger, and a display. The handle has a second axis and includes a first recess configured to receive the battery pack. The second axis forms an oblique angle with the first axis, and the battery pack is inserted into the first recess along the second axis. The clamp is coupled to the main body, aligned with the first axis, and operable to measure an electrical characteristic of a conductor based on an induced current. Various features and advantages of the invention are set forth in the following claims.

Claims (22)

What is claimed is:

1. A clamp meter configured to receive a removable and rechargeable battery pack, the clamp meter comprising:

a main body having a first axis;

a handle having a second axis and including a first recess configured to receive at least a portion of the battery pack, the first recess including first and second electrical terminals which are exposed when the at least a portion of the battery pack is not inserted in the first recess;

wherein the second axis forms an oblique angle with the first axis;

a clamp extending along the first axis coupled to and supported by the main body, the clamp operable to measure an electrical characteristic of a conductor based on an induced current, the clamp including a first jaw and a second jaw;

a trigger operable to selectively open and close the clamp, the trigger positioned below the main body in a second recess of the handle,

a ram supported in the main body, wherein the trigger is operable to move the ram along the first axis toward the first jaw and the second jaw to open the clamp, the ram causing the first jaw to rotate about a first pivot axis and the second jaw to rotate about a second pivot axis to open the clamp; and

a display configured to display an indication of an electrical characteristic of a conductor.

2. The clamp meter ofclaim 1, further comprising a non-contact voltage detector.

3. The clamp meter ofclaim 1, further comprising an LED flashlight.

4. The clamp meter ofclaim 3, wherein the LED flashlight is operable to illuminate a first area enclosed by the clamp.

5. The clamp meter ofclaim 3, wherein the trigger is operable to activate the LED flashlight.

6. A clamp meter configured to receive a removable and rechargeable battery pack, the clamp meter comprising:

a main body having a first axis;

a handle having a second axis and including a first recess configured to receive at least a portion of the battery pack, the first recess including first and second electrical terminals which are exposed when the at least a portion of the battery pack is not inserted in the first recess;

wherein the second axis forms an oblique angle with the first axis;

a clamp coupled to and supported by the main body, the clamp operable to measure an electrical characteristic of a conductor based on an induced current, the clamp including a first jaw and a second jaw;

a trigger operable to selectively open and close the clamp, the trigger positioned below the main body in a second recess of the handle,

a ram, wherein the trigger is operable to move the ram toward the first jaw and the second jaw to open the clamp, the ram causing the first jaw to rotate about a first pivot axis and the second jaw to rotate about a second pivot axis to open the clamp; and

a display configured to display an indication of an electrical characteristic of a conductor;

wherein the trigger is operable to activate the LED flashlight;

wherein the trigger is operable to activate the LED flashlight when the trigger is engaged a first distance, and the trigger is operable to open the clamp when the trigger is engaged a second distance.

7. The clamp meter ofclaim 6, wherein the second distance is greater than the first distance.

8. The clamp meter ofclaim 1, wherein the battery pack is a lithium-ion battery pack.

9. A method of operating a clamp meter, the clamp meter including a main body having a first axis, a handle, a clamp supported by the main body and including a first jaw and a second jaw, a trigger positioned below the main body, a ram supported in the main body, and a display, the method comprising:

powering the clamp meter with a removable battery pack, at least a portion of the battery pack being inserted into a recess of the handle, wherein the handle includes a second axis;

opening the clamp with the trigger, the trigger moving the ram along the first axis toward the first jaw and the second jaw, the ram causing the first jaw to rotate about a first pivot axis and the second jaw to rotate about a second pivot axis to open the clamp;

sensing, using the clamp, a first electrical characteristic based on an induced current,

wherein the clamp extends along the first axis, and

wherein the first axis and the second axis form an oblique angle; and

displaying, on the display, an indication of the first electrical characteristic.

10. The method ofclaim 9, wherein the battery pack is a lithium-ion battery pack.

11. The method ofclaim 9, further comprising detecting a voltage using a non-contact voltage detector.

12. The method ofclaim 11, further comprising activating a voltage sense indicator when the voltage is detected.

13. The method ofclaim 9, further comprising illuminating an area enclosed by the clamp using a flashlight powered by the battery pack.

14. The method ofclaim 13, wherein the flashlight is an LED flashlight.

15. The method ofclaim 14, wherein the LED flashlight is integral to the clamp meter.

16. The method ofclaim 13, further comprising activating the flashlight with the trigger.

17. A method of operating a clamp meter, the clamp meter including a main body having a first axis, a handle, a clamp supported by the main body and including a first jaw and a second jaw, a trigger positioned below the main body, a ram, and a display, the method comprising:

powering the clamp meter with a removable battery pack, at least a portion of the battery pack being inserted into a recess of the handle, wherein the handle includes a second axis;

opening the clamp with the trigger, the trigger moving the ram toward the first jaw and the second jaw, the ram causing the first jaw to rotate about a first pivot axis and the second jaw to rotate about a second pivot axis to open the clamp;

sensing, using the clamp, a first electrical characteristic based on an induced current,

wherein the clamp is aligned along a second axis, and

wherein the first axis and the second axis form an oblique angle; and

displaying, on the display, an indication of the first electrical characteristic;

further comprising activating the flashlight with the trigger;

wherein the flashlight is activated by the trigger when the trigger is at a first distance, and the clamp is opened when the trigger is at a second distance.

18. The method ofclaim 17, wherein the second distance is greater than the first distance.

19. The method ofclaim 9, further comprising measuring, based on signals received through a pair of electrical leads, a second electrical characteristic, wherein the pair of electrical leads are operable to receive a pair of electrical probes.

20. The method ofclaim 19, further comprising displaying, on a display, an indication of the second electrical characteristic.

21. The clamp meter ofclaim 1, wherein the trigger is operated in a plane including the first axis and the second axis to move the ram along the first axis.

22. The method ofclaim 9, wherein opening the clamp with the trigger includes operating the trigger in a plane including the first axis and the second axis to move the ram along the first axis.

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